Image processor, image processing method, recording medium, computer program and semiconductor device

ABSTRACT

An image processor is provided which utilizes images taken by an imaging device, e.g., a digital camera, as an input interface to enter commands, etc. Such image processor includes a memory operable to store an image from a series of real time images of a location captured by an imaging device over time, the stored image at least partially including a target that is subject to movement from one point in the time to another point in the time. The image processor further includes a detector operable to detect the target and a movement component thereof by detecting features of the captured images at different points in the time, and includes an image generator operable to generate an object image representing a predetermined object so that a color of a predetermined portion of the object image varies according to the detected movement component of the target. Such image generator is further operable to generate a combined image from the object image and the stored image and to output in real time a signal representing the combined image, to permit the combined image to be displayed to the location imaged by the imaging device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/971,962 filed Oct. 5, 2001 now U.S. Pat. No. 6,771,277, thedisclosure of which is hereby incorporated by reference herein. Thatapplication is based upon and claims the benefit of priority from theprior Japanese Patent Applications Nos. 2000-307574, filed Oct. 6, 2000,and 2001-295098 filed Sep. 26, 2001, the entire contents of both ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to an image processing technology forusing an image taken by an image pickup apparatus such as a video cameraas an interface for inputting commands, etc.

A keyboard, mouse, controller, etc. are input devices often used for acomputer, video game machine, etc. The operator inputs desired commandsby operating these input devices to render a computer, etc. to executeprocessing according to the commands entered. Then, the operator seesimages and listens to sound, etc. obtained as the processing resultsfrom a display device and speaker.

The operator enters commands by operating many buttons provided on theinput device while watching a cursor shown on the display device.

Such operations greatly depend on operating experiences of the operator.For example, for a person who never touched the keyboard before,entering desired commands using the keyboard is quite troublesome andtime-consuming, and prone to input errors due to mistyping from thekeyboard. For this reason, there is a demand for a man-machine interfacethat will provide the operator with an easy way to operate.

On the other hand, with the progress of multimedia technologies, peoplein general households can now readily enjoy capturing images using avideo camera into a computer, etc., editing and displaying the images ona display device. Such technologies are also used for personalauthentication by analyzing images of a physical body such as a face,extracting characteristic parts thereof to identify individuals.

Conventionally, these images are used as information to be processed bya computer such as editing or analysis. However, images taken have notbeen used so far for a purpose such as entering commands to a computer,for example.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an image processingtechnology to use images taken by an image pickup apparatus, etc. as aninput interface to enter commands, etc.

According to an aspect of the invention, an image processor is providedwhich utilizes images taken by an imaging device, e.g., a digitalcamera, as an input interface to enter commands, etc. Such imageprocessor includes a memory operable to store an image from a series ofreal time images of a location captured by an imaging device over time,the stored image at least partially including a target that is subjectto movement from one point in the time to another point in the time. Theimage processor further includes a detector operable to detect thetarget and a movement component thereof by detecting features of thecaptured images at different points in the time, and includes an imagegenerator operable to generate an object image representing apredetermined object so that a color of a predetermined portion of theobject image varies according to the detected movement component of thetarget. Such image generator is further operable to generate a combinedimage from the object image and the stored image and to output in realtime a signal representing the combined image, to permit the combinedimage to be displayed to the location imaged by the imaging device.

The “target” refers to a remarked part of an object (person or matter,etc.) whose image is taken by an image pickup apparatus that suppliesthe image to an image processor. An image processor is provided whichutilizes images taken by an imaging device, e.g., a digital camera, asan input interface to enter commands, etc.

Another image processor provided according to another aspect of theinvention includes a memory operable to store an image from a series ofreal time images of a location captured by an imaging device over time,the stored image at least partially including a target that is subjectto movement from one point in the time to another point in the time. Theimage processor further includes a detector operable to detect thetarget and a movement component thereof by detecting features of thecaptured images at different points in the time, and includes an imagegenerator operable to generate an object image representing apredetermined object so that the object image follows a movement of thedetected target and includes an image representing a trace of themovement. Such image generator is further operable to generate acombined image from the object image and the stored image and to outputin real time a signal representing the combined image, to permit thecombined image to be displayed to the location imaged by the imagingdevice.

These image processors generate object images according to the movementsof targets included in the mirrored moving image. That is, the movement,color, shape of the object image to be displayed on the display deviceand if there is a plurality of object images, which object image shouldbe displayed, etc. are determined by the movement of the target. Forexample, if the target is the operator, the object is determinedaccording to the movement of the operator. Thus, the mirrored movingimage is available as a kind of input interface.

It is also possible to comprise means for making preparations forexecuting required processing based on the generated object imageaccording to the movement component of the target.

It is also possible to further comprise means for comparing a combinedimage obtained by combining the object image generated by the imagegenerating means and the mirrored moving image at the actual time point,with a template image which is the image of part of the target includedin the immediately preceding mirrored moving image, detecting the partof the combined image whose image feature is most resembling thetemplate image and making preparations for executing required processingbased on this object image when the image of the part of the detectedcombined image includes the object image.

By associating the object image with predetermined processing andfurther comprising means for executing the processing linked to theobject image when the movement component of the target detected by thedetecting means satisfies predetermined conditions, it is possible toexecute processing using the movement of the target as an input.

It is also possible to construct the image processor so that themirrored moving image includes a plurality of targets, construct thedetecting means to detect the movement components of the plurality oftargets and detect one target based on the respective movementcomponents of the detected plurality of targets, construct the imagegenerating means to change the object image according to the movementcomponent of the one target detected by the detecting means.

According to another aspect of the invention, an imaging processingmethod is provided having steps including storing an image from a seriesof real time images of a location captured by an imaging device overtime, the stored image at least partially including a target that issubject to movement from one point in the time to another point in thetime; detecting the target and a movement component thereof by detectingfeatures of the captured images at different points in the time;generating an object image representing a predetermined object so that acolor of a predetermined portion of the object image varies according tothe detected movement component of the target; generating a combinedimage from the object image and the stored image; outputting in realtime a signal representing the combined image, to permit the combinedimage to be displayed to the location imaged by the imaging device.

According to still other aspects of the invention, a recording medium isprovided having instructions recorded thereon for performing a methodsuch as described above, and a semiconductor device is provided whichhas functions to perform such method.

BRIEF DESCRIPTION OF THE DRAWINGS

These objects and other objects and advantages of the present inventionwill become more apparent upon reading of the following detaileddescription and the accompanying drawings in which:

FIG. 1 is an overall configuration diagram of an image processing systemapplying the present invention;

FIG. 2 is a configuration diagram of an image processor according to anembodiment of the present invention;

FIG. 3 is a functional block diagram of the image processor according tothe embodiment of the present invention;

FIG. 4 is a flow chart showing a processing procedure of Embodiment 1;

FIG. 5 is a flow chart showing a processing procedure of Embodiment 1;

FIG. 6 illustrates a combined image according to Embodiment 1;

FIG. 7 illustrates a menu image;

FIG. 8 is a flow chart showing a processing procedure of Embodiment 2;

FIG. 9 illustrates a combined image according to Embodiment 2;

FIG. 10 is a view illustrating a drawing using a recursive texture;

FIG. 11 is a flow chart showing a processing procedure of Embodiment 3;

FIG. 12 is a flow chart showing a processing procedure of Embodiment 3;and

FIG. 13 illustrates a combined image according to Embodiment 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will be specifically describedwith reference to the drawings accompanying herewith.

FIG. 1 is a configuration example of an image processing system applyingthe present invention.

This image processing system takes pictures of the operator who sits infront of a display device 3 using an analog or digital video camera 1.In this way, the image processing system captures moving images into animage processor 2 consecutively in a time series to generate mirroredmoving images. Of these mirrored moving images, the image processingsystem combines object images expressing objects such as a menu andcursor at positions where remarked objects such as the eyes and hands ofthe operator (hereinafter the remarked objects are referred to as“targets”) to generate a combined image (this, too, becomes a movingimage) and displays this combined image on the display device 3 in realtime.

A mirrored moving image can be generated by subjecting the moving imagecaptured from the video camera 1 to mirroring (right/left inversion ofimage) by the image processor 2, but it is also possible to place amirror in front of the video camera 1 and take pictures of a movingimage on the mirror surface reflecting the operator by the video camera1 to form a mirrored moving image. In any case, a combined image whosedisplay mode changes in real time according to the movement of thetarget is displayed on the display device 3.

The image processor 2 is implemented by a computer that forms therequired functions using a computer program.

The computer according to this embodiment whose hardware configurationis shown by way of example in FIG. 2 has two buses; a main bus B1 andsub bus B2 to which a plurality of semiconductor devices each havingspecific functions is connected. These buses B1 and B2 are mutuallyconnected or disconnected via a bus interface INT.

The main bus B1 is connected to a main CPU 10 which is a mainsemiconductor device, a main memory 11 made up of a RAM, a main DMAC(Direct Memory Access Controller) 12, an MPEG (Moving Picture ExpertsGroup) decoder (MDEC) 13 and a graphic processing unit (hereinafterreferred to as “GPU”) 14 incorporating a frame memory 15 which serves asa drawing memory. The GPU 14 is connected with a CRTC (CRT controller)16 for generating a video signal so as to display the data drawn in theframe memory 15 on the display device 3.

The CPU 10 loads a start program from the ROM 23 on the sub bus B2 atthe startup via the bus interface INT, executes the start program andoperates an operating system. The CPU 10 also controls the media drive27, reads an application program or data from the medium 28 mounted inthis media drive 27 and stores this in the main memory 11. The CPU 10further applies geometry processing (coordinate value calculationprocessing) to various data read from the medium 28, for example,three-dimensional object data (coordinate values of vertices (typicalpoints) of a polygon, etc.) made up of a plurality of basic graphics(polygons) and generates a display list containing geometry-processedpolygon definition information (specifications of shape of the polygonused, its drawing position, type, color or texture, etc. of componentsof the polygon).

The GPU 14 is a semiconductor device having the functions of storingdrawing context (drawing data including polygon components), carryingout rendering processing (drawing processing) by reading necessarydrawing context according to the display list notified from the main CPU10 and drawing polygons in the frame memory 15. The frame memory 15 canalso be used as a texture memory. Thus, a pixel image in the framememory can be pasted as texture to a polygon to be drawn.

The main DMAC 12 is a semiconductor device that carries out DMA transfercontrol over the circuits connected to the main bus B1 and also carriesout DMA transfer control over the circuits connected to the sub bus B2according to the condition of the bus interface INT. The MDEC 13 is asemiconductor device that operates in parallel with the CPU 10 and hasthe function of expanding data compressed in MPEG (Moving PictureExperts Group) or JPEG (Joint Photographic Experts Group) systems, etc.

The sub bus B2 is connected to a sub CPU 20 made up of a microprocessor,etc., a sub memory 21 made up of a RAM, a sub DMAC 22, a ROM 23 thatrecords a control program such as operating system, a sound processingsemiconductor device (SPU: Sound Processing Unit) 24 that reads sounddata stored in the sound memory 25 and outputs as audio output, acommunication control section (ATM) 26 that transmits/receivesinformation to/from an external apparatus via a network (not shown), amedia drive 27 for setting a medium 28 such as CD-ROM and DVD-ROM and aninput device 31.

The sub CPU 20 carries out various operations according to the controlprogram stored in the ROM 23. The sub DMAC 22 is a semiconductor devicethat carries out control such as a DMA transfer over the circuitsconnected to the sub bus B2 only when the bus interface INT separatesthe main bus B1 from sub bus B2. The input unit 31 is provided with aconnection terminal 32 through which an input signal from an operatingdevice 35 is input, a connection terminal 33 through which an imagesignal from a video camera 1 is input and a connection terminal 34through which a sound signal from the video camera 1 is input.

This Specification will only explain about images and omit explanationsof sound for convenience.

In the computer constructed as shown above, and with reference to FIG.3, the main CPU 10, sub CPU 20 and GPU 14 read and execute apredetermined computer program from the recording medium such as the ROM23 and medium 28, and thereby form a functional block necessary foroperating as the image processor 2, that is, an image input device 101,an image inverter 102, an object data storage device 103, an object datainput device 104, an object controller 105, a superimposing imagegenerator 106, a difference value detector 107 and a display controller108.

In the relationship with the hardware shown in FIG. 1, the image inputdevice 101 is formed by the input device 31 and the sub CPU 20 thatcontrols the operation thereof, the image inverter 102, the object datainput device 104, the object controller 105 and the difference valuedetector 107 are formed by the CPU 10 and the superimposing imagegenerator 106 are formed by the GPU 104, and the display controller 108is formed by the GPU 14 and CRTC 16 cooperating with each other. Theobject data storage device 103 is formed in a memory area accessible tothe main CPU 10, for example, the main memory 11.

The image input device 101 incorporates images taken by the video camera1 via the connection terminal 33 of the input device 31. In the casewhere the image entered is a digital image, the image input device 101incorporates the image as is. In the case where the image taken andentered is an analog image, the image input device 101 incorporates theimage after converting it from analog to digital.

The image inverter 102 subjects the image incorporated by the imageinput device 101 to mirroring, that is, right/left inversion to form amirrored moving image.

The object data storage device 103 stores object data to express objectssuch as a menu (including a submenu), matchstick, and cursor togetherwith identification data thereof.

The object data input device 104 incorporates necessary object data fromthe object data storage device 103 and sends the object data to theobject controller 105. The object data to be incorporated is instructedby the object controller 105.

The object controller 105 generates an object image based on the objectdata incorporated from the object data input section 104 according tothe instruction content. Especially, the object controller 105determines the object display condition based on a difference value sentfrom the difference value detector 107 and generates an object image torealize the display condition. The difference value will be describedlater.

The superimposing image generator 106 draws a combined image obtained bysuperimposing the mirrored moving image output from the image inverter102 on the object image generated by the object controller 105 in theframe memory 15.

By the way, in addition to generating a combined image by superimposingthe object image, it is also possible to display the object image on themirrored moving image using publicly known imposing processing.

The difference value detector 107 compares the image features of themirrored moving image of the combined image generated by thesuperimposing image generator 106 frame by frame and derives thedifference value of the image features between the mirrored movingimages of the preceding and following frames. Furthermore, thedifference value detector 107 generates a difference image between themirrored moving images of the preceding and following frames asrequired.

The difference value in the image features is a value quantitativelyexpressing a variation per frame of the movement component of the targetincluded in the mirrored moving image. For example, the difference valueindicates a distance that the target has moved in the mirrored movingimage or an area between the area after the movement and the area beforethe movement.

When a plurality of targets is included within one mirrored movingimage, a difference value in the image features expresses a variation inthe movement of each target, and therefore it is possible toquantitatively calculate the variation in the movement of each target bycalculating this difference value.

The difference image is an image expressing a variation in the movementper frame of each target included in the mirrored moving image at everypoint in time. For example, when a target moves between two mirroredmoving images, the difference image is an image made up of the image ofthe target before the movement and the image of the target after themovement.

In order to derive the difference value and difference image, thedifference value detector 107 stores a certain mirrored moving image asa “reference image” relative to mirrored moving images of other framesin the main memory 11. The mirrored moving image to be stored may be afull one-frame worth mirrored moving image or may be a mirrored movingimage that is only part of the target because all that is required is tomake it possible to derive a difference value in the image features.

In the following explanations, whenever a distinction should be madebetween an image of part of a target and an image of the rest of thetarget, such an image is called “template image”.

The difference value detected by the difference value detector 107 issent to the object controller 105 and used to control movements ofobject images.

The display controller 108 converts the combined image generated bysuperimposing image generator 106 to a video signal and outputs thevideo signal to the display device 3. The display device 3 displays thecombined image (moving image) on a screen using this video signal.

<Image Processing Method>

An embodiment of the image processing method carried out using theabove-described image processing system will now be explained.

[Embodiment 1]

On the display device 3, as shown in FIG. 6, suppose the image processor2 displays a combined image consisting of the mirrored moving image ofthe operator taken by the video camera 1 and subjected to mirroring witha menu image as an example of an object image superimposed.

As a target, it is possible to select various objects such as the eyes,mouth, hands, etc. of the operator. Here, a case will be described wherethe operator's hand is the target and instructions are entered to themenu image by detecting the amount of movement of the hand in the areain which the menu image is displayed.

The menu image has a hierarchic structure as shown in FIG. 7. When theoperator selects “menu” at the top layer, a pull-down image highlightingone of “select1”, “select2” or “select3” at the lower layer is displayedand when one item is selected from the pull-down image, the processdetermining image (for example, “process 21”, “process 22”, “process23”, “process 24”) of the menu at the lower layer of the selectedpull-down image are displayed.

The process determining image is stored in the object data storagedevice 103 linked to the program to render the main CPU 10 to executethe determined process (event) and when a certain process determiningimage is selected, the program linked thereto starts to execute thecorresponding process (event).

FIG. 4 and FIG. 5 show the procedure for processing by the imageprocessor 2 to enable such an operation.

First, with reference to FIG. 4, the difference value detector 107updates the mirrored moving image to that of the next frame and when thecombined image generated by the superimposing image generator 106 isthereby updated (step S101), image features of the mirrored moving imageincluded in the preceding and following combined images to be updatedare compared and the difference value is calculated (step S102). Thedifference value calculated here is a value expressing one movement ofthe operator's hand in the area in which the menu image is displayed.The difference values calculated are recorded in the main memory 11 andcumulatively added for a certain period of time (step S103). The reasonthat difference values are cumulatively added is that the operator'swill about the operation instruction is detected by the image processor2 based on a plurality of movements of the operator's hand. If theoperator's will about the operation instruction can be checked accordingto the amount of one time movement of the hand, cumulative addition neednot always be performed.

The difference value detector 107 sends the difference value (cumulativesum) to the object controller 105.

The object controller 105 determines the color of the menu imageaccording to the difference value (cumulative sum) received from thedifference value detector 107 (step S104). For example, a plurality ofcolors of the menu image is provided and the color is changed one by oneevery time a movement of the hand is detected. It is also possible tochange the color from transparent to semitransparent, opaque, etc. Orthe actual difference value (cumulative sum) is compared with apredetermined threshold (step S105) and if the cumulative sum is smallerthan the threshold (step S105: N), the routine goes back to step S101assuming that it is not sufficient to determine that “menu” of the menuscreen has been selected.

When the cumulative sum exceeds the threshold (step S105: Y), the objectcontroller 105 determines that “menu” of the menu screen has beenselected, shows a pull-down image and reports it to the difference valuedetector 107 (step S106).

Thus, when the cumulative sum of the movement of the operator's handdetected in the area in which the menu image is displayed exceeds thethreshold, the object controller 105 detects that “menu” of the menuimage has been selected and shows the pull-down image. The color of themenu image changes according to the cumulative sum of the amount ofmovement of the hand, and therefore the operator can know a rough amountof additional movement of the hand required to select “menu”.

Furthermore, since the display device 3 shows a mirrored moving image,the operator can perform the above-described operation in much the sameway the operator looks in a mirror, providing a man-machine interfaceeasy-to-operate for the operator.

Thus, according to FIG. 5, when it is detected that “menu” on the menuscreen has been selected, that is, the difference value (cumulative sum)has exceeded the threshold, the difference value detector 107 stores theimage of the operator's hand (target) at that time as a template image(step S107).

When the frame is updated and the menu image is thereby replaced by thepull-down image in its subordinate layer and a combined image is shown(step S108), a search is started for the location of the image of theoperator's hand in the new combined image. That is, the difference valuedetector 107 searches for an image that matches the template image fromthe combined image (step S109).

More specifically, the difference value detector 107 divides thecombined image into areas in the same size as that of the template imageand searches for the image most resembling the template image from amongthe images in the respective areas after the division. The image mostresembling the template image in the area is, for example, when the sumtotal of absolute values (or squares) of differences between pixels ofthe images compared can be expressed as distances, an image whosedistance from the template image is a minimum.

When a matched image is found (step S110: Y), it is determined whetherthe matched image is a pull-down image or not (step S111). If thematched image is a pull-down image (step S111: Y), the area of thepull-down image is detected from “select1”, “select2” or “select3” (stepS112). The detected pull-down image becomes the pull-down imageindicated and selected by the operator. Information on the selectedpull-down image is reported from the difference value detector 107 tothe object controller 105.

The object controller 105 reads a process-determining image accompanyingthe selected pull-down image from the object data storage device 103 andgenerates an object image to which this process-determining image isattached (step S113).

In this way, the display device 3 shows how the menus are selected oneafter another by the operator.

In the example in FIG. 7, the pull-down image of “select2” is selectedfrom the menu image at the top layer and the process determining images(“process 21”, “process 22”, “process 23” and “process 24”) accompanyingthe pull-down image of “select2” are displayed.

The template image is replaced by a new one for every frame.

That is, the difference value detector 107 discards the template imageused for the preceding frame and stores the above-described matchedimage (image of the operator's hand used to select the pull-down image)as a new template image (step S114). Then, the routine returns to stepS108 to specify any one of the process determining images (“process 21”,“process 22”, “process 23” and “process 24”) as shown above.

In step S111, when the matched image is outside the area of thepull-down image but is any one of the process determining images withinthe process determining image area (step S111: N, S115: Y), the processdetermining image is assumed to have been selected and the content ofthe process linked thereto is determined, that is, the program is madeexecutable and the process using the menu image is finished (step S118).

When the matched image is outside the areas of the pull-down image andthe process determining image but within the menu image area (step S111:N, S115: N, S116: Y), this means that the operator attempts to selectanother pull-down image, and therefore the routine discards the templateimage, stores the matched image as a new template image and returns tostep S108 (step S117).

In step S110, when no matched image to be compared is found (step S110:N) or when a matched image is found but is an image outside the area ofthe menu image, the process by the menu image is finished at that time(step S111: N, S115: N, S116: N).

By carrying out processing according to the menu image in the aboveprocedure, the operator can easily select the process with a desiredcontent while watching the own mirrored moving image shown on the screenof the display device 3. Furthermore, the operator can enterinstructions while checking the own behavior on the screen at any time,which prevents the operator from averting his/her eyes from the displaydevice 3 as in the case of using an input device such as a keyboard.

[Embodiment 2]

The image processing system according to this embodiment links an objectimage to a program that causes the main CPU 10 to execute an event to besubjected to image processing so that processing of the relevant eventis executed according to the action of the operator within the mirroredmoving image on the object image.

As an example of an object image to be superimposed on the mirroredmoving image, this embodiment shows a case of using an image of amatchstick and an image of a flame expressing that the matchstickignites and burns.

As a premise, the image of the matchstick, which is the object image, islinked beforehand to a program to display an ignition animationindicating that the matchstick has ignited on the display device 3.Then, when the operator in the mirrored moving image behaves as ifhe/she struck the image of the match within the combined image, theignition animation is designed to appear in the ignition part of theimage of the matchstick. The image of the flame is displayed when theoperator strikes the image of the matchstick.

The image of the flame can be generated using a technique of, forexample, recursive texture drawing.

The “recursive texture drawing” refers to a drawing technique ofreferencing an image of an object rendered by texture mapping as textureof another image and carrying out texture mapping recursively. “Texturemapping” is a technique of rendering an image of an object to enhancethe texture of the image by pasting bitmap data of the texture to thesurface of the object and can be implemented by also using the framememory 15 as a texture memory. When carrying out such recursive texturedrawing, gouraud shading is applied to a polygon on which the texture isdrawn, that is, the brightness at vertices of the polygon is calculatedand the brightness inside the polygon is calculated by interpolating thebrightness of each vertex (this technique is called “gouraud shadingdrawing”).

To express the flame image, the positions of vertices of a mesh which isthe source of the flame image are shifted using random numbers as shownin FIG. 10 and the positions of new vertices are determined. Thebrightness at the vertices is also determined based on random numbers.The positions of the vertices and brightness at the vertices aredetermined every time the frame is updated. Every unit of the mesh whichis the source of the flame image becomes a polygon.

On each polygon, the image that becomes the basis of the flame drawn inthe frame memory 15 is formed through the above-described recursivetexture drawing and the above-described gouraud shading is applied basedon the brightness at each vertex of the polygon. This makes it possibleto express a rising air current caused by the flame, shimmering,attenuation of the flame in a more realistic way.

Suppose the image processor 2 shows a combined image with the image of amatchstick superimposed on the mirrored moving image of the operator onthe display device 3. Here, suppose the target is the operator's hand.By detecting the amount of movement of the hand in the area in which theimage of the matchstick is displayed, the program linked to the image ofthe matchstick is executed and the ignition animation is displayed onthe display device 3.

FIG. 8 shows the processing procedure using the image processor 2 torealize such an operation.

When the mirrored moving image is updated to the image of the next frameand the combined image generated by the superimposing image generator106 is thereby updated (step S301), the difference value detector 107compares image features of the mirrored moving images included in thecombined images before and after the updating, calculates a differencevalue of the image in the ignition section of the image of thematchstick and generates a difference image of the ignition section ofthe image of the matchstick (step S202). The difference value calculatedhere is a value that quantitatively expresses the movement of the handin the ignition section of the image of the matchstick. The differencevalue generated is an image made up of the images of the hand before andafter moving the hand in the ignition section of the image of thematchstick.

The calculated difference value is recorded in the main memory 11 andcumulatively added for a certain period of time (step S203)

The difference value detector 107 sends the cumulative sum, which is thecumulative sum of the difference images and difference values to theobject controller 105.

The object controller 105 determines the color of the difference imageaccording to the cumulative sum received from the difference valuedetector 107 and generates a flame image based on this difference image(step S204). The flame image is generated, for example, by dividing thedifference image into meshes and using the aforementioned recursivetexture based on these meshes. The color of the flame image isdetermined according to the color of the difference image. The flameimage generated is superimposed on the ignition section of the image ofthe matchstick.

In this way, the flame image with the color according to the amount ofmovement of the hand added is displayed in the area showing the movementof the hand in the ignition section of the image of the matchstick.

Determining the color of the flame image according to the cumulative sumof difference values makes it possible, for example, to express how thecolor of the flame image displayed in the ignition section of thematchstick gradually changes according to the amount of movement of thehand.

Then, the object controller 105 compares the value indicating the colorof the flame image with a predetermined threshold (step S205). Forexample, if the color of the flame image is expressed by R, G and Bvalues, the sum of their respective values can be used.

When the value indicating the color is equal to or greater than thethreshold (step S205: Y), the object controller 105 determines toexecute the program that displays the ignition animation indicating thatthe match has ignited (step S206).

That is, whether or not to start the ignition animation is determinedaccording to the color of the flame image. For example, when the colorof the flame image changes from red to yellow according to the amount ofmovement of the hand, the ignition animation starts when the flameimages turns yellow. The operator can know a rough amount of additionalmovement of the hand required to start the ignition animation.

The superimposing image generator 106 generates a combined imagesuperimposing the ignition animation on the object image including thematchstick image and flame image, on the mirrored moving image obtainedfrom the video camera 1 (step S207). The ignition animation is displayedin the ignition section of the matchstick image.

When the value indicating the color is smaller than the threshold (stepS205: N), the object controller 105 sends the object image superimposingthe flame image on the matchstick image to the superimposing imagegenerator 106. The superimposing image generator 106 generates acombined image by superimposing this object image on the mirrored movingimage obtained from the video camera 1 (step S208).

Then, if, for example, an instruction for finishing the processing isreceived from the operation device 35, the processing is finished (stepS209: Y). If no instruction for finishing the processing is received(step S209: N), the routine returns to step S201 and the displaycontroller 108 displays the combined image generated in step S207 orstep S208 on the display device 3.

As shown above, the system executes the process of determining whetheror not to execute the program for displaying the ignition animationlinked to the matchstick image according to how much the operator moveshis/her hand in the ignition section of the matchstick image.

Since the operator can perform operations for executing various eventswhile watching the mirrored moving image, it is possible to performinput operations for executing processes more easily than conventionaloperations using input devices such as a keyboard and mouse.

[Embodiment 3]

Another embodiment will now be explained. As a premise, suppose theimage processor 2 shows a combined image with a cursor (pointer) image,which is an example of an object image, superimposed on the mirroredmoving image of the operator on the display device 3 as shown in FIG.13( a). Also suppose a plurality of targets such as the hand, eyes,mouth of the operator are included in the mirrored moving image.

Here, a case will be explained whereby focusing on the movement of theoperator's hand from the plurality of these targets, the cursor image isexpressed in such a way as to follow this movement of the hand.

As shown in FIG. 13( a), the cursor image is an image like a face withan emphasis put on the eyes, which allows the eyes to be oriented towardthe target. Furthermore, the cursor image moves following the movementof the target. That is, when the cursor image is distant from thetarget, the cursor image moves toward the target and when the cursorimage catches the target, the cursor image follows the movement of thetarget.

FIG. 11 and FIG. 12 show the processing procedure using the imageprocessor 2 to realize such an operation.

According to FIG. 11, when the mirrored moving image is updated to theimage of the next frame and the combined image generated by thesuperimposing image generator 106 is thereby updated (step S301), thedifference value detector 107 compares image features of the mirroredmoving image included in the combined images before and after theupdating and calculates the difference value thereof (step S302) Thedifference value calculated here is a value quantifying the movements ofthe hands, eyes, mouth, etc. of the operator, which become candidates ofthe target in the mirrored moving image.

The difference value detector 107 sends the difference value of eachtarget to the object controller 105.

The object controller 105 detects one target based on the differencevalue of each target sent from the difference value detector 107 (stepS303). For example, the object controller 105 detects a target whosedifference value reaches a maximum. In this example, suppose theoperator's hand is detected as the target.

Upon detecting the target, the object controller 105 determines how thecursor image is displayed according to the target.

First, the object controller 105 determines whether the target in thecombined image updated in step S310 is outside the cursor image or not(step S304). If the target is within the cursor image (step S304: N),the object controller 105 determines that the cursor image has caughtthe target (step S308).

If the target is outside the cursor image (step S304: Y), the objectcontroller 105 determines that the cursor image has not caught thetarget and carries out processing for determining how the cursor imageis displayed. That is, the object controller 105 generates a cursorimage so that the eyes in the cursor image are oriented toward thetarget.

Furthermore, the object controller 105 determines the speed at which thecursor image moves toward the target according to the distance betweenthe cursor image and target (step S306). This speed is adjusted toincrease as the cursor image moves away from the target. This makes itpossible to obtain an image in which the cursor moves toward the targetfaster as the cursor image stays farther from the target.

The superimposing image generator 106 superimposes such a cursor imageon the mirrored moving image of the next frame and thereby generates acombined image as shown in FIG. 13( a) (step S307). Then, the routinegoes back to step S301 and performs the same operation for the combinedimage generated.

The routine carries out the operations of step S301 to S307 until thecursor image catches the target, that is, until it is determined in stepS304 that the target is within the cursor image.

Such operations can provide an image as shown in FIG. 13( a) in whichthe eyes in the cursor image are oriented toward the target (hand) andthe cursor image chases after the target.

Then, according to FIG. 12, when the cursor image catches the target,the difference value detector 107 stores the image of the target at thattime as a template image (step S309). For example, the difference valuedetector 107 stores the section of the mirrored moving image thatoverlaps with the cursor image as the template image.

Then, the difference value detector 107 acquires the mirrored movingimage of the next frame from the image inverter 102 (step S310) Thedifference value detector 107 searches for the position of an image thatmatches the stored template image from among the acquired mirroredmoving images (step S311).

More specifically, the difference value detector 107 divides theacquired mirrored moving image into areas of the same size as thetemplate image and searches for an image in the area most resembling thetemplate image from among the images in the respective divided areas.Upon detecting the matched image as a result of the search, thedifference value detector 107 reports the position of the detected imageto the object controller 105.

The object controller 105 determines the position reported from thedifference value detector 107 as the position of the cursor image forthe next combined image (step S312).

The superimposing image generator 106 superimposes the cursor image atthe position determined in step S312 by the object controller 105 on thesame mirrored moving image as the mirrored moving image acquired in stepS310 by the difference value detector 107 and thereby generates acombined image as shown in FIG. 13( b) (step S313). Then, the frame isupdated and the display controller 108 displays the combined imagegenerated on the display device 3 (step S314).

Repeating the above-described operations after the target is caught(step S309 to step S314) obtains an image in which the cursor imagefollows the target. That is, when the cursor image catches the target(hand) as shown in FIG. 13( b), the cursor image is displayed thereafterfollowing the target wherever the target moves. Even when the operatorextends the hand as shown in FIG. 13( b) to FIG. 13( c), the cursorimage is displayed at the tip of the extended hand of the operatortogether with the movement of the hand recognized as the target.

Use of the cursor image allows the operator to know at a glance whichposition of the part of the own body is functioning as the cursor whenselecting a process from the menu image as shown in Embodiment 1, forexample.

Furthermore, if, for example, the trace of the movement of the cursorimage is set to be kept and displayed, it is possible to show the traceof the movement of the target on the display device 3. This makes itpossible to show, for example, pictures and characters, etc. drawn inthe space on the display device 3.

As is clear from the foregoing explanations, when the operator needs toenter data, etc. the present invention allows the operator to enter orselect the data easily using the mirrored moving image while watchingthe combined image displayed on the display device, and can therebyprovide a user-friendly input interface without the need to getaccustomed thereto.

Various embodiments and changes may be made there unto without departingfrom the broad spirit and scope of the invention. The above-describedembodiment intended to illustrate the present invention, not to limitthe scope of the present invention. The scope of the present inventionis shown by the attached claims rather than the embodiment. Variousmodifications made within the meaning of an equivalent of the claims ofthe invention and within the claims are to be regarded to be in thescope of the present invention.

1. An image processor, comprising: (a) a memory operable to store inreal time a series of images of a location captured by an imaging deviceover time, the captured series of images at least partially including atarget that is subject to move within the captured series of images fromone point in the time to another point in the time; (b) a detectoroperable to detect the target and a quantitative value of a movementcomponent thereof by detecting differences between features of thecaptured series of images at a first point in the time and at a secondpoint in the time; (c) an image generator operable to generate an objectimage representing a predetermined object so that a color of apredetermined portion of the object image varies according to thedetected quantitative value of the movement component of the target, theimage generator being further operable to generate a combined image fromthe object image and an image from the captured series of images; and(d) an output operable to output in real time a signal representing thecombined image at the location captured in the series of images.
 2. Theimage processor according to claim 1, wherein the combined imageincludes a mirrored image of the target.
 3. The image processoraccording to claim 1, wherein the output is operable to output thesignal representing the combined image to a predetermined displaydevice.
 4. The image processor according to claim 1, wherein the targetis a first target, the captured series of images includes a plurality oftargets including the first target each being subject to move within thecaptured series of images from one point in the time to another point inthe time, and the detector is operable to detect the quantitative valueof the movement component of each of the plurality of targets and todetect a particular one of the plurality of targets based on thedetected quantitative values of the movement components of the pluralityof targets such that the image generator is operable to change the colorof the object image according to the detected quantitative value of themovement component of the particular target.
 5. The image processoraccording to claim 1, wherein the object image is associated withpredetermined processing and the image generator is further operable toperform the predetermined processing when the detected quantitativevalue of the movement component satisfies a predetermined condition. 6.The image processor according to claim 1, wherein the detectedquantitative value of the movement component includes a rate of movementof the target.
 7. The image processor according to claim 1, wherein thedetected quantitative value of the movement component includes acumulative amount of movement of the target.
 8. The image processor asclaimed in claim 7, wherein the image generator is operable to generatethe object image so that the object image changes when the detectedcumulative amount of movement of the target exceeds a threshold.
 9. Animage processing method, comprising: storing in real time a series ofimages of a location captured by an imaging device over time, thecaptured series of images at least partially including a target that issubject to move within the captured series of images from one point inthe time to another point in the time; detecting the target and aquantitative value of a movement component thereof by detectingdifferences between features of the captured series of images at a firstpoint in the time and at a second point in the time; generating anobject image representing a predetermined object so that a color of apredetermined portion of the object image varies according to thedetected quantitative value of the movement component of the target;generating a combined image from the object image and an image from thecaptured series of images; and outputting in real time a signalrepresenting the combined image at the location captured in the seriesof images to display the combined image at the location.
 10. Acomputer-readable recording medium having instructions recorded thereon,the instructions being executable by a computer or image processingsystem to perform a method, the method comprising: storing in real timea series of images of a location captured by an imaging device overtime, the captured series of images at least partially including atarget that is subject to move within the captured series of images fromone point in the time to another point in the time; detecting the targetand a quantitative value of a movement component thereof by detectingdifferences between features of the captured series of images at a firstpoint in the time and at a second point in the time; generating anobject image representing a predetermined object so that a color of apredetermined portion of the object image varies according to thedetected quantitative value of the movement component of the target;generating a combined image from the object image and an image from thecaptured series of images; and outputting in real time a signalrepresenting the combined image at the location captured in the seriesof images.
 11. A system operable to process an image, comprising: a oneor more semiconductor devices, the one or more semiconductor devicesincluding: (a) a memory operable to store in real time a series ofimages of a location captured by an imaging device over time, thecaptured series of images at least partially including a target that issubject to move within the captured series of images from one point inthe time to another point in the time, (b) a detector operable to detectthe target and a quantitative value of a movement component thereof bydetecting differences between features of the captured series of imagesat a first point in the time and at a second point in the time, (c) animage generator operable to generate an object image representing apredetermined object so that a color of a predetermined portion of theobject image varies according to the detected quantitative value of themovement component of the target, the image generator being furtheroperable to generate a combined image from the object image and an imagefrom the captured series of images, and (d) an output operable to outputin real time a signal representing the combined image at the locationcaptured in the series of images.